Immune system

Imagine that your body is a castle and your immune system is your army fighting off invaders like bacteria. If your army malfunctions and attacks the castle, you may have lupus, multiple sclerosis, rheumatoid arthritis and/or psoriasis, among a hundred other autoimmune diseases. You may experience pain, fatigue, dizziness, rashes, depression and many more symptoms. Overview What are autoimmune diseases? Your immune system is made up of organs and cells meant to protect your body from bacteria, parasites, viruses and cancer cells. An autoimmune disease is the result of the There are over 100 known autoimmune diseases. Common ones include lupus, rheumatoid arthritis, Crohn’s disease and ulcerative colitis. Autoimmune diseases can affect many types of tissues and nearly any organ in your body. They may cause a variety of symptoms including pain, tiredness (fatigue), rashes, nausea, headaches, dizziness and more. Specific symptoms depend on the exact disease. How do autoimmune diseases work? Experts don’t know why your immune system turns on you. It’s like it can no longer tell the difference between what’s healthy and what’s not — between what’s you and what’s an invader. There are some theories about why this happens, but experts aren’t completely sure. What’s a list of autoimmune diseases? Some common autoimmune diseases include: Diseases of the joints and muscles: • • • • Diseases of the digestive tract: • • • Diseases of the endocrine system: • • • Diseases of the skin: •...

The immune system distinguishes self from nonself and eliminates potentially harmful nonself molecules and cells from the body. The immune system also has the capacity to recognize and destroy abnormal cells that derive from host tissues. Any molecule capable of being recognized by the immune system is considered an antigen (Ag). Outer, keratinized epidermis: Keratinocytes in the skin secrete antimicrobial peptides (defensins), and sebaceous and sweat glands secrete microbe-inhibiting substances (eg, lactic acid, fatty acids). Also, many immune cells (eg, mast cells, intraepithelial lymphocytes, antigen-sampling Langerhans cells) reside in the skin. • Many molecular components (eg, Complement System The complement system is an enzyme cascade that helps defend against infection. Many complement proteins occur in serum as inactive enzyme precursors (zymogens); others reside on cell surfaces... read more , Cytokines The immune system consists of cellular components and molecular components that work together to destroy antigens (Ags). (See also Overview of the Immune System.) Acute phase reactants are plasma... read more , Acute Phase Reactants The immune system consists of cellular components and molecular components that work together to destroy antigens (Ags). (See also Overview of the Immune System.) Acute phase reactants are plasma... read more ) participate in both innate and acquired immunity. Innate immunity Innate (natural) immunity does not require prior exposure to...

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. We’ve all heard that when you’re sick, Can eating certain foods really boost your immune system? While no single food is a magic cure when you’re sick, eating a healthy diet full of vitamins and minerals that support your immune system can boost your immunity, which can prevent illness and help you bounce back sooner when you do get sick. “There’s no doubt that a healthy diet improves your immunity to illness,” says immunologist As your immune system is your body’s defense against invaders like the Dr. Calabrese talks about foods that boost immunity during flu season and all year round. Fatty fish Eat more • Albacore tuna. • Herring. • Mackerel. • • Sardines. • Trout. Some Citrus fruits You’ve probably guzzled orange juice when you were sick, hoping the vitamin C would work its magic on any germs floating around in your body. • • Lemons. • Limes. • Grapefruits. Garlic Eating this pungent vegetable comes with plenty of health benefits like improving your heart health. But Try adding garlic to your Ginger A mainstay in Asian and Indian cuisines, the spice has also been used for centuries in Eastern medicine. And that’s for a good reason — And while you may find yourself using ginger in your baking and wintertime lattes or teas, know that it may also help ease inflammation and nausea in addition to adding a f...

Contents • 1 Layered defense • 2 Surface barriers • 3 Innate immune system • 3.1 Immune sensing • 3.2 Innate immune cells • 3.3 Inflammation • 3.4 Humoral defenses • 4 Adaptive immune system • 4.1 Recognition of antigen • 4.2 Antigen presentation to T lymphocytes • 4.3 Cell mediated immunity • 4.3.1 Killer T cells • 4.3.2 Helper T cells • 4.3.3 Gamma delta T cells • 4.4 Humoral immune response • 4.5 Immunological memory • 5 Physiological regulation • 5.1 Hormones • 5.2 Vitamin D • 5.3 Sleep and rest • 5.4 Physical exercise • 5.4.1 Changes at the cellular level • 5.5 Repair and regeneration • 6 Disorders of human immunity • 6.1 Immunodeficiencies • 6.2 Autoimmunity • 6.3 Hypersensitivity • 6.4 Idiopathic inflammation • 7 Manipulation in medicine • 7.1 Immunosuppression • 7.2 Immunostimulation • 7.3 Vaccination • 7.4 Tumor immunology • 7.5 Predicting immunogenicity • 8 Evolution and other mechanisms • 8.1 Evolution of the immune system • 8.2 Alternative adaptive immune system • 8.3 Manipulation by pathogens • 9 History of immunology • 10 See also • 11 References • 11.1 Citations • 11.2 General bibliography • 12 Further reading • 13 External links Layered defense The immune system protects its host from Components of the immune system Response is non-specific Pathogen and Exposure leads to immediate maximal response Lag time between exposure and maximal response No immunological memory Exposure leads to immunological memory Found in nearly all forms of life Found only in Both...

Your immune system is your body’s defense againstinfections and other harmfulinvaders. Without it, you would constantly get sick frombacteria or viruses. Your immune system is made up of special cells, tissues, and organs that work together to protect you. The lymph, or lymphatic, system is a major part of the immune system. It's a network of lymph nodes and vessels. Lymphatic vessels are thin tubes that branch, like blood vessels,throughout the body. They carry a clear fluid called lymph. Lymph contains tissue fluid, waste products, and immune system cells. Lymph nodes are small, bean-shaped clumps of immune system cells that are connected by lymphatic vessels. They contain white blood cells that trap viruses, bacteria, and other invaders, including cancer cells. White blood cells are the cells of the immune system. They are made in one of your lymph organs, the bone marrow. Other lymph organs include thespleen and thymus. What can go wrong with your immune system? When your immune system doesn't work the way it should, it is called an immune system disorder. You may: • Beborn with a weak immune system. This is called primary immune deficiency. • Get a disease that weakens your immune system. This is called acquired immune deficiency. • Have animmune system that is too active.This may happen with an allergic reaction. • Have animmune system thatturns against you. This is called autoimmune disease. Immune systemdisorders Here are some common examples: • Severe combined imm...

• Adenoid or pharyngeal tonsil: Located in the back of the nose, above the throat ( • Tubal tonsils: Located where the pharynx connects with the tube leading to the ear (the Eustachian tube) and are a subsite of the adenoid tonsils • Palatine tonsils: Located in your throat, near the roof of your mouth, which a healthcare provider can see when shining a light into your throat • Lingual tonsils: Located at the base of the tongue • Pus-filled infection of nearby tissue ( peritonsillar abscess), which may cause severe throat pain, lockjaw, or a muffled voice • Kidney infection ( glomerulonephritis), which can cause swelling, high blood pressure, and decreased urine (pee) output • Rheumatic fever, which can lead to joint pain and heart problems Seek emergency medical attention for potentially life-threatening symptoms like severe difficulty breathing, sudden chest pain, or decreased consciousness. Palatine Tonsils Removal Some people with repeated tonsillitis may need a tonsillectomy (surgery to remove the tonsils). Guidelines from the American Academy of Otolaryngology—Head and Neck Surgery Foundation advise that children might benefit from tonsillectomy if they’ve had: The American Academy of Otolaryngology does not recommend tonsil removal for recurrent ear infections. However, if Summary The palatine tonsils are located at the back of your mouth. They are made up of lymphatic tissue that is important for fighting infections. Most of the time, when people say “tonsils,” the...

Overview Primary immunodeficiency disorders — also called primary immune disorders or primary immunodeficiency — weaken the immune system, allowing infections and other health problems to occur more easily. Many people with primary immunodeficiency are born missing some of the body's immune defenses or with the immune system not working properly, which leaves them more susceptible to germs that can cause infections. So far, researchers have identified more than 300 forms of primary immunodeficiency disorders. Some forms are so mild they can go unnoticed until adulthood. Other types are severe enough that they're discovered soon after an affected baby is born. Treatments can boost the immune system in many types of primary immunodeficiency disorders. Research is ongoing, leading to improved treatments and enhanced quality of life for people with the condition. Symptoms One of the most common signs of primary immunodeficiency is having infections that are more frequent, longer lasting or harder to treat than are the infections of someone with a typical immune system. You may also get infections that a person with a healthy immune system likely wouldn't get (opportunistic infections). Signs and symptoms differ depending on the type of primary immunodeficiency disorder, and they vary from person to person. Signs and symptoms of primary immunodeficiency can include: • Frequent and recurrent pneumonia, bronchitis, sinus infections, ear infections, meningitis or skin infections •...